In Bitcoin Core the transaction id is appended with a dash and three numbers. They are usually 000. What do those numbers mean?
For example: b75b91ffc4b6f22b779ce45e4b140cf1d29dc894e368e3d8389c42444f870d5d-000
It's the index of the output in the transaction that credits you.
It's a bit of an unused format; typically ':n' is used, rather than '-nnn'.
This is because an entry in the transaction ledger doesn't really corresponding to one transaction, but to one output of it. For example, a transaction could have multiple outputs that all credit you.